Conventionally, as an apparatus for measuring the blood sugar level, an apparatus combining a puncturing device for making a scar on a fingertip and a measuring device attached with a disposable blood sensor for sampling a small amount of blood squeezed from the fingertip where the scar is made, is widely used.
However, if such a puncturing device and a measuring device are provided separately, the patient needs to puncture the skin with the puncturing device and then sample blood using the measuring device, which makes the measuring operation complex.
Therefore, a blood test apparatus that integrates a lancet with a puncturing needle and a measuring device to which a blood sensor is attached, is proposed (see Patent Document 1). As shown in FIG. 13, proposed blood test apparatus 1 has cylinder-shaped housing 2, plunger 3 that moves back and forth inside housing 2, lancet 4 that has one end 4a held by plunger 3 and the other end 4b attached with blood collection needle 5, and blood sensor 6 attached to one end 2a of housing 2.
Test steps using blood test apparatus 1 will be described. First, blood sensor 6 is made to abut on skin 7, which is the part to be punctured, of the patient. Next, latch convex part 9a of handle 9 connected to plunger 3 and latch concave part 2b formed on housing 2 are disengaged. Plunger 3 urged by spring 10 is thereby propelled in the direction of arrow 8. In response to this, lancet 4 held by plunger 3 and blood collection needle 5 attached to this lancet 4 are also propelled in the direction of arrow 8.
Propelled needle 5 goes through blood sensor 6 and makes a tiny scar on skin 7. The blood flowing out from this scar is detected by a detecting section of blood sensor 6. A signal obtained according to the glucose in blood is led to measuring circuit 12 from connection electrode 6a via connector 11. Measuring circuit 12 calculates the blood sugar level of the sampled blood and displays the calculation result on display section 13.    Patent Document 1: Japanese Patent Application Publication No. 2003-524496